A wireless power-supplying system that performs power supply safely and efficiently without a foreign matter intruding into a space between a power-receiving unit provided on the bottom of a vehicle and a power-supplying unit embedded in a parking space is disclosed in Patent Document 1 below. In the wireless power-supplying system, an insulating isolation material is provided in the space between the power-receiving unit of the vehicle and the power-supplying unit of the parking space, stored in the ground at the time of non-power-supply, and moved into the space between the power-receiving unit and the power-supplying unit by a movable unit at the time of power supply. Particularly, when a metallic foreign matter intrudes, serious problems are caused in power transfer, such as degradation in transfer efficiency due to the influence of the metallic foreign matter.